In downshifts that involve an interlocking shifting element, for example a claw clutch, it is known from the prior art that the synchronization of the interlocking shifting element can be actively assisted by controlling the engine behavior, namely by positive action upon the torque or by appropriate control of the rotational speed.
However, this has the disadvantageous result that precisely in the case of coasting downshifts, i.e. gearshifts with a negative engine torque, the shift becomes a traction shift. The consequence is that this change of condition leads to a cross-over of the engine and turbine rotational speeds, which can be perceptible and impairs comfort for the driver.
This is particularly noticeable when the action upon the engine is discontinued and the engines rotational speed falls back again with a steep gradient below the turbine rotational speed, which in the prior art is the case shortly before the end of the shift and gives rise to a perceptible jerk. Furthermore, the slight difference between the turbine rotational speed and the engine rotational speed existing in the prior art at the moment when the claw clutch is engaged, also increases the risk that the engagement of the claws of the claw clutch will be perceptible.